PROJECT SUMMARY/ABSTRACT Most COPD patients remain unrecognized and undertreated; these individuals experience impaired health status, acute respiratory deteriorations, increased mortality and high health care utilization. Targeted case finding to date has generally identified patients without reference to spirometric severity or exacerbation (ECOPD) risk. We have developed a simple case finding tool using five questions combined with selective peak expiratory flow measurement (CAPTURE) that identifies individuals with ?clinically significant COPD,? those most likely to benefit from currently available therapies. Our long-term goal is to effectively identify these individuals so therapy can improve health status, reduce ECOPD, and decrease morbidity. The overall objectives of this proposal are to validate the sensitivity, specificity, and predictive value of CAPTURE to identify undiagnosed, clinically significant COPD in a diverse primary care population; to confirm that this methodological approach can be integrated into a variety of primary clinical care settings; and explore whether identifying these patients results in improved COPD specific care and health status. Our central hypothesis is that CAPTURE can effectively and efficiently identify primary care patients with undiagnosed, clinically significant COPD. The rationale for the proposed research is that the answer to three simple questions will change the paradigm for COPD diagnosis in primary care: 1) Is CAPTURE effective in identifying patients with clinically significant COPD; 2) Does CAPTURE work in primary care settings; and 3) does CAPTURE make a difference in the lives of patients with previously undiagnosed, clinically significant COPD. Guided by strong preliminary data we will pursue three specific aims: 1) We will determine the sensitivity and specificity of CAPTURE in identifying clinically significant COPD in a broad range of primary care outpatient practices; 2) We will define the feasibility of using CAPTURE in 10 practices representing a wide range of primary care clinical settings across the US; 3) We will explore the impact of our case finding approach in a broad range of primary care outpatient practices and evaluate practice and patient level characteristics that are associated with COPD related care implementation and clinical outcomes. These aims will be accomplished in a 5,000 subject cohort study in 75 primary care practices affiliated with five primary care based research networks that provide access to previously undiagnosed patients who exhibit ethnic, racial, socioeconomic and regional diversity. In a subset of these clinical practices we will complete a detailed feasibility analysis of CAPTURE implementation. Our approach is highly innovative and clinically relevant as it applies a rigorously developed, novel COPD case finding approach to identifying COPD patients most likely to benefit from available therapy. The proposed research is significant, as the results will change the paradigm for COPD diagnosis in primary care and change COPD recommendations globally.